Telephone-transmitter.



J. Z. MILLER.

TELEPHONE TRANSMITTER. APPLICATION FILED 00119.1904.

PATENTED JAN 9; 1906.

nnirn srarns JOHN Z. MILLER, OF ERIE, PENNSYLVANIA.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

Patented Jan. 9, 1906.

Application filed October 19,1904. Serial No. 229,171.

To all whom it may concern:

Be it known that I, J OHN 7i. MILLER, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania, have invented new and useful Improvements in Telephone-Transmitters, of which the following is a specification.

This invention relates to telephone-transmitters; and it consists in certain improvements in the construction thereof, as will be hereinafter fully described, and pointed out in the claims.

The invention is illustrated in the accompanying drawings, as follows:

Figure 1 is an elevation of the mouthpiece; Fig. 2, a section on the line 2 2 in Fig. 3; Fig. 3, a view from the bottom of Fig. 2; Fig. l, an elevation of the shell for the back of the case.

The transmitter is mounted in the case A, which has the screw-threads a for receiving the mouthpiece D. A back plate B, preferably formed of rigid conducting material, is secured to the case by the screws C. The washer E, formed of a fabric, preferably felt, is arranged on the back plate B. The elec trode F is placed within the washer E in con tact with the plate B. A granulated conducting material G is placed in the space above the electrode F, so as to form a variable conductor on which the diaphragm H may act. I preferably interpose a second electrode F, which is mounted on the diaphragm H and extends into the cavity in the washer. The diaphragm H extends over and closes the cavity in the washer, it being mounted in contact with the washer and in position to contact the granulated conducting material G. The diaphragm is mounted on a ring H, formed of conducting material and insulated from the case and back plate by insulating-rings h, h, and 7L2. A conductor I leads from the ring through an opening I) in the back plate to a terminal J, the terminal being mounted on the insulatingblock The block is mounted on the back plate. The back of the transmitter proper is inclosed by a shell K, which is secured to the case by the screws It. The shell is of such diameter and shape as to fit the outer wall a of the case. By this construction the essential parts of the transmitter are entirely inclosed and practically moisture-proof, thus assuring durability and uniformity of operation. This is accomplished by making the rings h and h of a comparatively soft insulating material, so as to seal the transmitter against any moisture that may enter through the mouthpiece. The washer E forms a damper which modulates the vibrations of the diaphragm, thus giving a more accurate reproduction of the sounds transmitted. The comparatively rigid back plate in connection with the granulated material gives uniformity of microphone effect.

hat I claim as new is 1. In a telephone-transmitter, the combination of a non-vibrating back plate; a washer of fibrous and non-conducting material form ing a container; and dampener mounted on the back plate; an electrode arranged witoin the washer, the electrode being of less thick ness than the washer; granulated conducting material in the cavity with the electrode; a ring of conducting material arranged outside of said washer and mounted within the case but insulated from the case and back plate; and a diaphragm mounted on said ring and in electric contact with said ring and being connected with the back plate through the electrode and material in the cavity and the washer.

2. In a telephonetransmitter, the combination of the case A having a cavity therein for containing the transmitting parts; a nonvibrating back plate secured to the case and closing said cavity; a fibrous washer mounted on the back plate; transmitting material arranged in the washer; thediaphragm H arranged over the washer and in contact with the transmitting material; the rin H on which the diaphragm is arranged; t 1e packing-rings 7L and 7t for sealing the space between the diaphragm and the back plate, and for insulating the diaphragm from the back plate and case the terminal J; and means for connecting said terminal with the diaphragm.

. 3. In a telepholie-transmitter, the combination of the case A having a cavity therein for containing the transmitting parts; a nonvibrating back plate secured to the case and closing said cavity; a fibrous washer mounted on the back plate; transmitting material arranged in the washer; the diaphragm I-I arranged over the washer and in contact with the transmitting material; the ring H on which the diaphragm is arranged; the packing-rings h and h for sealing the space be tween the diaphragm and the back plate, and my hand in the presence of two subscribing for insulating the diaphragm from the back Witnesses. plate and case the terminal J; means for connecting said terminal With the diaphragm; JOHN MILLER 5 and the shell K secured to the back of the Witnesses:

case and inclosing the plate. C. D. HIGBY,

In testimony whereof I have hereunto set J. H. KOCH. 

